1. Field of the Invention
The present invention relates to a bag clamping arrangement and, more particularly, an arrangement for automatically controlling the filling volume and overflow of a liquid conducted into a flexible bag which is clamped in the arrangement.
The conveyance into and collection of fluids or liquids in sealed flexible bags constituted of a liquid-impervious material at times necessitates the application of controls for handling any encountered overflow of such fluids. For instance, in certain applications, such as when directing urine from an indwelling catheter towards a plastic bag, the flow of the urine into the bag will generally cease upon the bag having been filled, thereby producing an adverse effect on the urinary functions. Current bag replacing practice necessitates the operative steps of either the disconnection of the filled bag and consequently replacement with a second empty bag, or the employment of an automatic or semi-automatic mechanical device for diverting the flow of urine or fluid from the filled bag which emanates from the catheter to a second empty bag. Thus, the replacement of a filled bag by manually disconnecting it from a catheter is encumbered with the risk of contamination by the fluid in the flow system; thereby requiring frequent inspection by operating personnel for the presence of any possible overflow and is, moreover, difficult and cumbersome to implement in actual practice. Additionally, mechanical overflow diversion devices or systems are generally complicated in structure and function, uneconomically expensive, and at times tend to fail during operation so as not to afford a sufficient degree of reliability.
Similarly, a bag clamping arrangement of the type described hereinabove may be required, upon occasion, for automatically diverting plasma from one flexible bag to another bag during the collection of plasma from a plasmapheresis device. In that instance, important requirements are the maintenance of a closed flow system for the plasma collection during its operation, a high degree of simplicity in operation, and ease of manufacture so as to render it economical. Frequently, any plasma which is collected in the flexible bag is subsequently rapidly processed through the quick freezing of the contents, in effect, the plasma, which necessitates that the liquid contents be present in a thin layer within the bag. Consequently, any flexible bag employed in such a plasma collecting system should be only filled to a proportion or certain percentage of its available fill volume, in contrast as would be the case for simple fluid containment, such as urine collection. In view of the foregoing, the inventive clamping arrangement also incorporates structural and functional features which will facilitate that the bag be filled with fluid or liquid up to only a predetermined part of its volume and in which any overflow may be diverted to a second bag which is similarly clamped in the bag clamping arrangement and connected to the first bag.
2. Discussion of the Prior Art
Although various types of bag clamping devices and arrangements are known in the art, none of these are adapted in any manner for the automatic control over the filling volume of flexible or plastic bags and the overflow of a fluid or liquid from such bags.
Schweizer U.S. Pat. No. 4,449,969 discloses a drainage receptacle construction for collecting body fluids having a support frame, wherein a flexible collecting bag is suspended from upright posts through eyelets which are formed in the bag for maintaining the vertical position of the bag, and which includes a clamping device engaging the lower end of the bag. Although this structure is utilized in connection with a drainage device for collecting urine from a patient, it fails to provide for the necessary control of the overflow of fluid from the filled bag and, in effect, necessitates that the filled bag be manually disconnected from a catheter communicating therewith, and thereafter be replaced by an empty bag which is then connected to the catheter.
Other bag holders and various types of bag clamping devices are disclosed in Benoit U.S. Pat. No. 3,653,620; Heitz U.S. Pat. No. 3,779,419; Larson U.S. Pat. No. 3,297,287; and Kleeberg U.S. Pat. No. 3,443,745. Although all of these U.S. patents disclose bag holding and clamping devices, none of these fulfill functions analogous to the inventive bag clamping arrangement which provides for the automatic control of the filling volume and/or overflow of fluids or liquids from a partly filled bag into a second empty bag retained in the clamping arrangement.